From past studies, stimulation from the natural and/or therapeutic environments of schizophrenic patients is hypothesized to exploit a central deficit, thereby precipitating relapse. An extensive naturalistic study of personal and environmental factors is being conducted, concurrent with a series of controlled aftercare treatment trials. One trial tests the assumption that the need for maintenance chemotherapy can be greatly influenced, if not governed, by the level of environmental stimuli (expressed emotion) and personal vulnerability (attention deficit). Within highly stressful environments, the source of expressed emotion is unclear. In another trial a variety of psychosocial-behavioral approaches is being experimentally controlled in an attempt to modify either family attitudes (Family Therapy) or patient behaviors (Social Skills Training). The methodology of both trials will be enhanced significantly if the effects of a stimulating environment can be measured by some objective, unobtrusive measure. In another study we are applying a new method capable of continuously monitoring motor behavior. The effects of an arousing environment on plasma levels of maintenance chemotherapy are also being studied. Greater clarification regarding the nature and type of personal and environmental vulnerability is being achieved through a series of small sub-studies which will contribute substantively to the test of principal hypotheses. It is believed that the results will provide a more rational basis for the aftercare treatment of schizophrenic disorders.